“I recommend this book for anyone
administering UNIX or Linux systems.”

David | 15
reviewers made a similar statement

“It's well written, easy to read and
very informative.”

Gary L.
Roach | 12 reviewers made a
similar statement

“Best Linux book I have purchased ever
to date.”

Josh | 15
reviewers made a similar statement

We are pleased to announce the completely updated fifth
edition of UNIX and Linux System Administration
Handbook! The book is published by
Addison-Wesley Professional.

“This edition is for those whose
systems live in the cloud or in virtualized data centers; those
whose administrative work largely takes the form of automation
and configuration source code; those who collaborate closely
with developers, network engineers, compliance officers, and all
the other worker bees who inhabit the modern hive.”

— from
the Foreword by Paul Vixie, Internet Hall of Fame-recognized
innovator and founder of ISC and Farsight Security

“As an author, editor, and publisher, I
never paid much attention to the competition— except
in a few cases. This is one of those cases. UNIX System
Administration Handbook is one of the few books we ever
measured ourselves against.”

— from
the 4th Edition Foreword by Tim O'Reilly, founder of O'Reilly
Media

About the book

UNIX and Linux System
Administration Handbook, Fifth Edition, is today’s definitive
guide to installing, configuring, and maintaining any UNIX or
Linux system, including systems that supply core Internet and
cloud infrastructure.

Updated for new distributions and cloud environments, this
comprehensive guide covers best practices for every facet of
system administration, including storage management, network
design and administration, security, web hosting, automation,
configuration management, performance analysis, virtualization,
DNS, security, and the management of IT service organizations.
The authors—world-class, hands-on technologists—offer
indispensable new coverage of cloud platforms, the DevOps
philosophy, continuous deployment, containerization, monitoring,
and many other essential topics.

Whatever your role in running systems and networks built on UNIX
or Linux, this conversational, well-written guide will improve
your efficiency and help solve your knottiest problems.

Errata for UNIX and Linux System Administration Handbook, 4E

We usually have the opportunity to make corrections before each
printing. Therefore, your book's complement of errors may vary depending
on its printing. To determine your printing, look at the last line of
the copyright page.

Page 33

The backquoted command wc -l /etc/passwd
seen in the page's last command line should actually
be wc -l < /etc/passwd.

The issue is that wc -l prints out
filenames as well as line counts when filenames are
supplied on the command line. Here, only the line
count is wanted.

p44

Page 44

Contrary to Table 2.2, bash has no string
equivalents to the numeric -le and -ge
operators. The >= and <=
operators listed in Table 2.2 do not exist.

The > and <
operators do exist. However, they must be
backslash-escaped or double bracketed to prevent
them from being interpreted as I/O redirection
characters.

p45

Page 45

The loop variable in the example for
loop is actually called script. The
text refers to it as file.

p51-52

Pages 51 and 52

The regular expression shown on pages 51–52 for
matching various spellings of Moammar Gadhafi's name
is OK as originally printed. However, the
accompanying text does not explain why the ([dtz][dhz]?)+
group (a component of the last name match) allows
repetition.

The + is there to accommodate
variants such as Quadhdhafi. Really, that fragment
should be ([dtz][dhz]?){1,2} so that
only one or two occurrences are permissible.

More generally, it's worth noting that this regex
is permissive. Not every string that it matches is a
legitimate spelling of Gadhafi's name. However, it
should match all legitimate spellings.

p153

Page 153

The cross-reference in the last line of the first
paragraph under The setuid and setgid bits
points to the wrong place.

The referenced material is on page 105, not page
106.

p466

Page 466

The route commands at the bottom of the
page are shell commands, not excerpts from a startup
script as the surrounding text might imply.

The # character indicates root's shell
prompt, not the comment character used in shell
scripts.

p574

Page 574

DNS Punycode names begin with xn--,
not xf-- as stated in the text.

p808

Page 808

In addition to having its own conventions, Debian's
version of Exim configuration uses the m4
preprocessor.

We don't describe the Debian system in this book.

p817

Page 817

There are two errors on this page.

In the sentence "The sender's address is not
checked because many user agents get confused by
error returns," replace "sender's address" with
"recipient's address."

The paragraph that starts "We next check the
destination domain..." claims that DKIM verification
is not performed during this step. That is
incorrect; DKIM is in fact enabled.

p821

Page 821

It is not entirely accurate to say that "If a
message receives a pass or decline
from all the routers in the sequence, it is bounced
as an unroutable address."

In fact, Exim may either bounce or reject such
messages, depending on the context.

p827

Page 827

Contrary to the statement in the Debugging
section, exim does fork when given the -d
flag. However, it does not detach itself from the
control terminal.

p852

Page 852

In the configuration file excerpt, the line that
sets dkim_selector should do a lookup
on $dkim_domain, not $sender_address_domain
as shown.

No formal errata are available for this printing
yet.
We will update this list after the next printing has
been finalized.

Frequently Asked Questions about ULSAH4E

I'm teaching a course that uses UNIX and Linux System
Administration Handbook as a textbook. Are there slides,
outlines, or other materials available for instructors?

Unfortunately, no. This is something we'd like to do, but
the scope of the book makes it likely that different courses will
choose to focus on different aspects of the material included in the
book. If you have specific suggestions for supplementary materials
that you would find helpful, please let
us know.

I'm interested in translating your book into another
language.

Translation and foreign sales rights are handled by
Prentice Hall. Please contact
us and we will put you in touch with the right people.

Is your book available as an eBook? What formats are
available?

ULSAH5E is available as a printed book, a Kindle book, a
Nook-compatible ePub book, a DRM-free PDF file, and as an online
resource through Safari Books
Online. Please see the links on the home page.

Hey! I found a mistake! You suck!

We usually have the opportunity to make corrections before
each printing. Please send
us a note describing the issue and we will make sure it is
addressed. (And thanks for your help!)

There's a problem with my printed copy of the book.

A small number of books were sent into distribution with
missing pages or with pages out of order. If you've ended up with one
of these copies, please let
us know and we will hook you up with a replacement.